c#调用非托管DLL出错的有关问题

c#调用非托管DLL出错的问题
原形
int   CFCA_VerifySignedDataDetached(char   *signature,     long   signatureLength,     char*   originalData,   int   *originalDataLength,   char   *certificate,     long   *certificateLength,   HCFCAToolkit   toolkitHandle);

signature                   输入
signatureLength 输入
originalData 输入
originalDataLength 输入
certificate 输出
certificateLength 输出
toolkitHandle 输入

转换成
[DllImport( "CFCAToolkit.dll ",   EntryPoint   =   "CFCA_VerifySignedDataDetached ",   SetLastError   =   true,
                CharSet   =   CharSet.Ansi,   CallingConvention   =   CallingConvention.Cdecl)]
                public   static   extern   int   CFCA_VerifySignedDataDetached(string   signature,   long   signatureLength,   string   originalData,   ref   int   originalDataLength,   char[]   certificate,   ref   long   certificateLength,   IntPtr   toolkitHandle);

调用报AccessViolationException异常，似乎是certificate这个参数传递造成的，请高手指点！

------解决方案--------------------
参数 char[] certificate 与原型中char *certificate不一致，你最好将char[] certificate
换成string certificate试一下
------解决方案--------------------
使用unsafe吧
------解决方案--------------------

参数 char[] certificate 与原型中char *certificate不一致，你最好将char[] certificate
换成string certificate试一下
------解决方案--------------------
帮LZ顶
------解决方案--------------------
char[] certificate换成string certificate